The present invention relates to a rotary linear drive having a linear drive device that has a primary part and a secondary part.
Rotary linear drives are generally known. Compared to rotary linear drives having an internal rotor, rotary linear drives having an external rotor for the linear drive have the advantage that they have a greater air gap area for the same outside diameter, and so higher axial forces can be produced.
Both the linear movement and the rotary movement of such rotary linear drives must be detected by appropriate transmitters so as to be controlled. However, magnetic detection devices suitable for this purpose are generally very sensitive to eccentricities between the transmitter magnets and the sensor.
Moreover, the placing of the magnetic field sensors of the transmitter devices is critical. They must in principle be shielded from the electromagnets and/or permanent magnets of the linear drive or be appropriately far removed from them.